1. Field of Disclosure
The present disclosure relates to an electron microscope for inspecting and processing an object with miniaturized structures and to a method for manufacturing an object with miniaturized structures, which method comprises processing and inspecting the object.
2. Background Information
Electron microscopy is a long time established method for inspecting a surface of an object to be examined. In scanning electron microscopy in particular the surface of the object to be examined is scanned using a narrow electron beam. The, due to the impingement of the electron beam, electrons escaping from the object surface or electrons backscattered from the object surface backscattered are detected, to be able to create an electron microscopic image of the scanned region. Conventionally, electron microscopes exhibit the following components: an electron beam source for generating an electron beam, an electron optics for focussing the electron beam onto the object to be examined, a deflecting optics for scanning the surface of the object using the electron beam as well as at least one detector for detecting electrons backscattered at the object surface or electrons escaping from the object surface. Beside for pure inspection electron microscopes are also increasingly employed for processing miniaturized structures on an object or for manufacturing an object with miniaturized structures. Thereby, material is selectively and with high precision deposited or ablated, by supplying a reaction gas to a location of the object which location is to be processed, wherein the reaction gas is excited by the electron beam impinging onto the location of the object to be processed and becomes chemically reactive, and thus by being able to selectively deposit material or selectively ablate material at the location of the excitation at the object surface. Thereby the reaction gas is appropriately selected in dependence of the material of a miniaturized structure on a surface of the object which material is to be ablated, respectively in dependence of the material to be deposited onto the surface of the object. A particular field of application of this technique lies in the domain of mask repair for lithography. For manufacturing miniaturized structures in the domain of semi-conductor industry masks still play an outstanding role. In the context of the lithography the (photo-) mask is traversed by light, to generate on a wafer a demagnified image of the mask, which exposes a photo resist applied onto a wafer and thus defines on the wafer in subsequent processing steps structures to be generated. Consequently, defects of the mask may adversely affect the quality of the miniaturized structures generated using the mask. Since the manufacturing of masks is still time consuming and expensive, methods for mask repair are increasingly applied. Thereby, using the described electron beam induced chemical reaction, mask defects can specifically and with high precision be repaired. In a method for mask repair, as also in other methods for generating miniaturized structures, it is required, to detect an end point of material deposition, respectively material ablation, at which a sufficient amount of material was deposited, respectively was ablated. For the detection of the end point a variety of parameters may be utilized for example signals from secondary or backscattered electrons, X-rays, gas components as well as a current generated in the object.